After Lookahead is generated, Constraints can be added to activities in the Masterplan and Lookahead.
Constraints represent the preparation work before an actual site work can be performed. Such preparation work could be contract, approval, material, safety, engineering design related, QA/QC or construction related submissions.
In Lean PlanDo, constraints are now categorised as Technical Constraints and Site Constraints. Preparation works such as approvals, permits, design specifications etc fall under the Technical constraints whereas all preparation works related to the construction site such as materials, labour, access space, temporary works etc fall under the Site constraints category.
Constraints can be added to an activity in the Masterplan or to a task and activity in the Lookahead.
Constraints are indicated as a grey circle and located on the due date planned and are in-lined with its activity.
A Constraint has status that can be set as 'Done' or 'Not Done'. Done constraint is shown as a green circle. The grey circle indicates that the constraint is not achieved yet. Red circle indicates the constraint is overdue and awaits update.
If a constraint due-date is set to a date such that the ETA (refer to Note below) is not maintained, the work (activity / task) is also delayed.
Conditions are the micro steps or prerequisites that help in detailed management and accomplishment of preparation works that need to be cleared for the actual work on-site to start.
Figure: Adding constraint from Gantt Chart
Figure: Details of the constraint
Figure: Status of the Constraint and its conditions
Note:
ETA (Estimated time of arrival) is the minimum number of days for the constraint to be resolved before the start of the work without delaying it.
Condition due dates are allowed only in increasing order. i.e. second condition due date should be the same or greater than the first one.
In any constraint, last condition due date will be the constraint due date.